Microresonators have received increasing attention in various applications such as optical switching described in, for example, U.S. Pat. No. 6,876,796; optical filtering described in, for example, U.S. Pat. No. 7,092,591; wavelength filtering described in, for example, U.S. Pat. No. 7,062,131; lasers described in, for example, U.S. Pat. No. 6,741,628; light depolarization described in, for example, U.S. Pat. No. 6,891,998; and chemical and biological sensing described in, for example, U.S. Pat. No. 5,744,902.
Some known microresonator constructions involve placing a glass spherical microresonator in close proximity to an optical waveguide such as an optical fiber. In such cases, optical energy can transfer between the resonator and the optical waveguide by evanescent coupling. The separation between the resonator and the optical waveguide is typically less than one micron and must be controlled with precision to provide reproducible performance. Other forms of microresonators include disk- or ring-shaped microresonators described in, for example, U.S. Pat. No. 7,095,010.